1. Field of the Invention
The present invention generally relates to surgical sutures, and more specifically relates to barbed sutures and devices used for affixing barbed sutures to tissue and prosthetic devices.
2. Description of the Related Art
Surgical sutures are used to close wounds and surgical incisions, and to repair damaged or severed muscles, vessels, and tissue. Typically, the suture is attached at one end to a needle, and the needle is drawn through tissue to form one or more loops holding the tissue together. The suture is subsequently tied off in one or more knots so that the tissue will remain drawn together.
Although sutures are very effective for closing wounds, there are a number of problems associated with using conventional sutures. Many of these troubles are directly related to the knots used to secure sutures in place. If the knots are not tied properly, defects may arise including slippage, knot breakage, and re-opening of the wound. In addition, using knots to secure sutures may distort tissue, restrict blood flow, increase the formation of scars, impede wound healing, and result in infection.
In response to the deficiencies associated with conventional sutures, sutures having barbs have been developed. Unlike conventional sutures, barbed sutures have projecting barbs that allow the suture to be used to close wounds, approximate tissue, tighten tissue, and attach prosthetic devices without using knots. Fixing conventional sutures with knots requires the knots to be pushed down toward the tissue to assure proper tensioning and fixation of the sutures. In contrast, barbed sutures achieve proper tensioning and fixation by applying tension to the suture. For example, U.S. Pat. No. 5,931,885 discloses barbed sutures that are used for cosmetic procedures such as brow-lifts and face-lifts.
In some procedures, it is desirable to use barbed sutures to secure prosthetic devices such as bioprosthetic heart valves. For example, in certain embodiments of commonly assigned U.S. Published Patent Application No. 2007/0005110, the disclosure of which is hereby incorporated by reference herein, braided barbed sutures are disposed in a heart valve sewing ring by first passing the sutures through an annulus and then passing the sutures through the valve sewing ring. Approximately 12-20 sets of braided barbed sutures are placed to secure the valve in place. The valve sewing ring is then parachuted down the sets of barbed sutures and seated in place within the annulus. After the sewing ring has been parachuted in a downward direction, the barbs prevent the sewing ring from being moved in the opposite, upward direction. Thus, the barbs hold the sewing ring in place without requiring knots.
When fixing barbed sutures to tissue or prosthetic devices, surgeons often use the tips of their fingers or the distal ends of surgical instruments (e.g. forceps) to apply pressure on the tissue or the prosthetic devices. These techniques may result in damage to the tissue, poor visibility at the surgical site due to the surgical site being blocked by the fingers or the surgical instruments, and insufficient or improper tensioning of the barbed sutures in the tissue or prosthetic devices. Conventional techniques also require many different instruments to be brought together to secure the barbed sutures in place, which may prove cumbersome.
When the above-described devices and techniques are used for applying tension to a barbed suture, the tissue is frequently stretched forming a tent-like shape due to the elastic properties of the tissue. This stretching may result in tissue trauma and poor control over the resulting tension that the barbed suture imparts on the tissue for either closing a wound or fixing a prosthetic device to the tissue.
At present, there are no devices that are specifically designed for aligning and tensioning barbed sutures. Thus, in spite of the above advances, there remains a need for systems, devices, and methods for properly aligning and tensioning barbed sutures in tissue and prosthetic devices. There also remains a need for a device that acts as a guide for the proper placement of barbed sutures, as well as a need for a device that provides sufficient visual access to surgical sites where barbed sutures are used.